isle-portable/miniwin/src/d3drm/backends/opengles2/renderer.cpp

718 lines
21 KiB
C++

#include "d3drmrenderer_opengles2.h"
#include "meshutils.h"
#include <GLES2/gl2.h>
#include <GLES2/gl2ext.h>
#include <SDL3/SDL.h>
#include <algorithm>
#include <string>
static GLuint CompileShader(GLenum type, const char* source)
{
GLuint shader = glCreateShader(type);
glShaderSource(shader, 1, &source, nullptr);
glCompileShader(shader);
GLint success;
glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
if (!success) {
glDeleteShader(shader);
SDL_Log("CompileShader (%s)", SDL_GetError());
return 0;
}
return shader;
}
struct SceneLightGLES2 {
float color[4];
float position[4];
float direction[4];
};
Direct3DRMRenderer* OpenGLES2Renderer::Create(DWORD width, DWORD height)
{
SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
SDL_Window* window = DDWindow;
bool testWindow = false;
if (!window) {
window = SDL_CreateWindow("OpenGL ES 2.0 test", width, height, SDL_WINDOW_HIDDEN | SDL_WINDOW_OPENGL);
testWindow = true;
}
SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
SDL_GLContext context = SDL_GL_CreateContext(window);
if (!context) {
if (testWindow) {
SDL_DestroyWindow(window);
}
return nullptr;
}
if (!SDL_GL_MakeCurrent(window, context)) {
if (testWindow) {
SDL_DestroyWindow(window);
}
return nullptr;
}
glDepthFunc(GL_LEQUAL);
glEnable(GL_CULL_FACE);
glCullFace(GL_BACK);
glFrontFace(GL_CW);
const char* vertexShaderSource = R"(
attribute vec3 a_position;
attribute vec3 a_normal;
attribute vec2 a_texCoord;
uniform mat4 u_modelViewMatrix;
uniform mat3 u_normalMatrix;
uniform mat4 u_projectionMatrix;
varying vec3 v_viewPos;
varying vec3 v_normal;
varying vec2 v_texCoord;
void main() {
vec4 viewPos = u_modelViewMatrix * vec4(a_position, 1.0);
gl_Position = u_projectionMatrix * viewPos;
v_viewPos = viewPos.xyz;
v_normal = normalize(u_normalMatrix * a_normal);
v_texCoord = a_texCoord;
}
)";
const char* fragmentShaderSource = R"(
precision mediump float;
struct SceneLight {
vec4 color;
vec4 position;
vec4 direction;
};
uniform SceneLight u_lights[3];
uniform int u_lightCount;
varying vec3 v_viewPos;
varying vec3 v_normal;
varying vec2 v_texCoord;
uniform float u_shininess;
uniform vec4 u_color;
uniform int u_useTexture;
uniform sampler2D u_texture;
void main() {
vec3 diffuse = vec3(0.0);
vec3 specular = vec3(0.0);
for (int i = 0; i < 3; ++i) {
if (i >= u_lightCount) break;
vec3 lightColor = u_lights[i].color.rgb;
if (u_lights[i].position.w == 0.0 && u_lights[i].direction.w == 0.0) {
diffuse += lightColor;
continue;
}
vec3 lightVec;
if (u_lights[i].direction.w == 1.0) {
lightVec = -normalize(u_lights[i].direction.xyz);
}
else {
lightVec = u_lights[i].position.xyz - v_viewPos;
}
lightVec = normalize(lightVec);
float dotNL = max(dot(v_normal, lightVec), 0.0);
if (dotNL > 0.0) {
// Diffuse contribution
diffuse += dotNL * lightColor;
// Specular
if (u_shininess > 0.0 && u_lights[i].direction.w == 1.0) {
vec3 viewVec = normalize(-v_viewPos); // Assuming camera at origin
vec3 H = normalize(lightVec + viewVec);
float dotNH = max(dot(v_normal, H), 0.0);
float spec = pow(dotNH, u_shininess);
specular += spec * lightColor;
}
}
}
vec4 finalColor = u_color;
finalColor.rgb = clamp(diffuse * u_color.rgb + specular, 0.0, 1.0);
if (u_useTexture != 0) {
vec4 texel = texture2D(u_texture, v_texCoord);
finalColor.rgb = clamp(texel.rgb * finalColor.rgb, 0.0, 1.0);
finalColor.a = texel.a;
}
gl_FragColor = finalColor;
}
)";
GLuint vs = CompileShader(GL_VERTEX_SHADER, vertexShaderSource);
GLuint fs = CompileShader(GL_FRAGMENT_SHADER, fragmentShaderSource);
GLuint shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, vs);
glAttachShader(shaderProgram, fs);
glBindAttribLocation(shaderProgram, 0, "a_position");
glBindAttribLocation(shaderProgram, 1, "a_normal");
glBindAttribLocation(shaderProgram, 2, "a_texCoord");
glLinkProgram(shaderProgram);
glDeleteShader(vs);
glDeleteShader(fs);
if (testWindow) {
SDL_DestroyWindow(window);
}
return new OpenGLES2Renderer(width, height, context, shaderProgram);
}
OpenGLES2Renderer::OpenGLES2Renderer(DWORD width, DWORD height, SDL_GLContext context, GLuint shaderProgram)
: m_context(context), m_shaderProgram(shaderProgram)
{
m_width = width;
m_height = height;
m_virtualWidth = width;
m_virtualHeight = height;
m_renderedImage = SDL_CreateSurface(m_width, m_height, SDL_PIXELFORMAT_RGBA32);
}
OpenGLES2Renderer::~OpenGLES2Renderer()
{
SDL_DestroySurface(m_renderedImage);
glDeleteProgram(m_shaderProgram);
}
void OpenGLES2Renderer::PushLights(const SceneLight* lightsArray, size_t count)
{
if (count > 3) {
SDL_Log("Unsupported number of lights (%d)", static_cast<int>(count));
count = 3;
}
m_lights.assign(lightsArray, lightsArray + count);
}
void OpenGLES2Renderer::SetFrustumPlanes(const Plane* frustumPlanes)
{
}
void OpenGLES2Renderer::SetProjection(const D3DRMMATRIX4D& projection, D3DVALUE front, D3DVALUE back)
{
memcpy(&m_projection, projection, sizeof(D3DRMMATRIX4D));
}
struct TextureDestroyContextGLS2 {
OpenGLES2Renderer* renderer;
Uint32 textureId;
};
void OpenGLES2Renderer::AddTextureDestroyCallback(Uint32 id, IDirect3DRMTexture* texture)
{
auto* ctx = new TextureDestroyContextGLS2{this, id};
texture->AddDestroyCallback(
[](IDirect3DRMObject* obj, void* arg) {
auto* ctx = static_cast<TextureDestroyContextGLS2*>(arg);
auto& cache = ctx->renderer->m_textures[ctx->textureId];
if (cache.glTextureId != 0) {
glDeleteTextures(1, &cache.glTextureId);
cache.glTextureId = 0;
cache.texture = nullptr;
}
delete ctx;
},
ctx
);
}
Uint32 OpenGLES2Renderer::GetTextureId(IDirect3DRMTexture* iTexture)
{
auto texture = static_cast<Direct3DRMTextureImpl*>(iTexture);
auto surface = static_cast<DirectDrawSurfaceImpl*>(texture->m_surface);
for (Uint32 i = 0; i < m_textures.size(); ++i) {
auto& tex = m_textures[i];
if (tex.texture == texture) {
if (tex.version != texture->m_version) {
glDeleteTextures(1, &tex.glTextureId);
glGenTextures(1, &tex.glTextureId);
glBindTexture(GL_TEXTURE_2D, tex.glTextureId);
SDL_Surface* surf = SDL_ConvertSurface(surface->m_surface, SDL_PIXELFORMAT_RGBA32);
if (!surf) {
return NO_TEXTURE_ID;
}
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, surf->w, surf->h, 0, GL_RGBA, GL_UNSIGNED_BYTE, surf->pixels);
SDL_DestroySurface(surf);
tex.version = texture->m_version;
}
return i;
}
}
GLuint texId;
glGenTextures(1, &texId);
glBindTexture(GL_TEXTURE_2D, texId);
SDL_Surface* surf = SDL_ConvertSurface(surface->m_surface, SDL_PIXELFORMAT_RGBA32);
if (!surf) {
return NO_TEXTURE_ID;
}
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, surf->w, surf->h, 0, GL_RGBA, GL_UNSIGNED_BYTE, surf->pixels);
for (Uint32 i = 0; i < m_textures.size(); ++i) {
auto& tex = m_textures[i];
if (!tex.texture) {
tex.texture = texture;
tex.version = texture->m_version;
tex.glTextureId = texId;
tex.width = surf->w;
tex.height = surf->h;
AddTextureDestroyCallback(i, texture);
return i;
}
}
m_textures.push_back({texture, texture->m_version, texId, (uint16_t) surf->w, (uint16_t) surf->h});
SDL_DestroySurface(surf);
AddTextureDestroyCallback((Uint32) (m_textures.size() - 1), texture);
return (Uint32) (m_textures.size() - 1);
}
GLES2MeshCacheEntry GLES2UploadMesh(const MeshGroup& meshGroup)
{
GLES2MeshCacheEntry cache{&meshGroup, meshGroup.version};
cache.flat = meshGroup.quality == D3DRMRENDER_FLAT || meshGroup.quality == D3DRMRENDER_UNLITFLAT;
std::vector<D3DRMVERTEX> vertices;
if (cache.flat) {
FlattenSurfaces(
meshGroup.vertices.data(),
meshGroup.vertices.size(),
meshGroup.indices.data(),
meshGroup.indices.size(),
meshGroup.texture != nullptr,
vertices,
cache.indices
);
}
else {
vertices = meshGroup.vertices;
cache.indices.resize(meshGroup.indices.size());
std::transform(meshGroup.indices.begin(), meshGroup.indices.end(), cache.indices.begin(), [](DWORD index) {
return static_cast<uint16_t>(index);
});
}
std::vector<TexCoord> texcoords;
if (meshGroup.texture) {
texcoords.resize(vertices.size());
std::transform(vertices.begin(), vertices.end(), texcoords.begin(), [](const D3DRMVERTEX& v) {
return v.texCoord;
});
}
std::vector<D3DVECTOR> positions(vertices.size());
std::transform(vertices.begin(), vertices.end(), positions.begin(), [](const D3DRMVERTEX& v) {
return v.position;
});
std::vector<D3DVECTOR> normals(vertices.size());
std::transform(vertices.begin(), vertices.end(), normals.begin(), [](const D3DRMVERTEX& v) { return v.normal; });
glGenBuffers(1, &cache.vboPositions);
glBindBuffer(GL_ARRAY_BUFFER, cache.vboPositions);
glBufferData(GL_ARRAY_BUFFER, positions.size() * sizeof(D3DVECTOR), positions.data(), GL_STATIC_DRAW);
glGenBuffers(1, &cache.vboNormals);
glBindBuffer(GL_ARRAY_BUFFER, cache.vboNormals);
glBufferData(GL_ARRAY_BUFFER, normals.size() * sizeof(D3DVECTOR), normals.data(), GL_STATIC_DRAW);
if (meshGroup.texture) {
glGenBuffers(1, &cache.vboTexcoords);
glBindBuffer(GL_ARRAY_BUFFER, cache.vboTexcoords);
glBufferData(GL_ARRAY_BUFFER, texcoords.size() * sizeof(TexCoord), texcoords.data(), GL_STATIC_DRAW);
}
glGenBuffers(1, &cache.ibo);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, cache.ibo);
glBufferData(
GL_ELEMENT_ARRAY_BUFFER,
cache.indices.size() * sizeof(cache.indices[0]),
cache.indices.data(),
GL_STATIC_DRAW
);
return cache;
}
struct GLES2MeshDestroyContext {
OpenGLES2Renderer* renderer;
Uint32 id;
};
void OpenGLES2Renderer::AddMeshDestroyCallback(Uint32 id, IDirect3DRMMesh* mesh)
{
auto* ctx = new GLES2MeshDestroyContext{this, id};
mesh->AddDestroyCallback(
[](IDirect3DRMObject*, void* arg) {
auto* ctx = static_cast<GLES2MeshDestroyContext*>(arg);
auto& cache = ctx->renderer->m_meshs[ctx->id];
cache.meshGroup = nullptr;
glDeleteBuffers(1, &cache.vboPositions);
glDeleteBuffers(1, &cache.vboNormals);
glDeleteBuffers(1, &cache.vboTexcoords);
glDeleteBuffers(1, &cache.ibo);
delete ctx;
},
ctx
);
}
Uint32 OpenGLES2Renderer::GetMeshId(IDirect3DRMMesh* mesh, const MeshGroup* meshGroup)
{
for (Uint32 i = 0; i < m_meshs.size(); ++i) {
auto& cache = m_meshs[i];
if (cache.meshGroup == meshGroup) {
if (cache.version != meshGroup->version) {
cache = std::move(GLES2UploadMesh(*meshGroup));
}
return i;
}
}
auto newCache = GLES2UploadMesh(*meshGroup);
for (Uint32 i = 0; i < m_meshs.size(); ++i) {
auto& cache = m_meshs[i];
if (!cache.meshGroup) {
cache = std::move(newCache);
AddMeshDestroyCallback(i, mesh);
return i;
}
}
m_meshs.push_back(std::move(newCache));
AddMeshDestroyCallback((Uint32) (m_meshs.size() - 1), mesh);
return (Uint32) (m_meshs.size() - 1);
}
void OpenGLES2Renderer::GetDesc(D3DDEVICEDESC* halDesc, D3DDEVICEDESC* helDesc)
{
halDesc->dcmColorModel = D3DCOLORMODEL::RGB;
halDesc->dwFlags = D3DDD_DEVICEZBUFFERBITDEPTH;
halDesc->dwDeviceZBufferBitDepth = DDBD_16;
const char* extensions = (const char*) glGetString(GL_EXTENSIONS);
if (extensions) {
if (strstr(extensions, "GL_OES_depth24")) {
halDesc->dwDeviceZBufferBitDepth |= DDBD_24;
}
if (strstr(extensions, "GL_OES_depth32")) {
halDesc->dwDeviceZBufferBitDepth |= DDBD_32;
}
}
helDesc->dwDeviceRenderBitDepth = DDBD_32;
halDesc->dpcTriCaps.dwTextureCaps = D3DPTEXTURECAPS_PERSPECTIVE;
halDesc->dpcTriCaps.dwShadeCaps = D3DPSHADECAPS_ALPHAFLATBLEND;
halDesc->dpcTriCaps.dwTextureFilterCaps = D3DPTFILTERCAPS_LINEAR;
memset(helDesc, 0, sizeof(D3DDEVICEDESC));
}
const char* OpenGLES2Renderer::GetName()
{
return "OpenGL ES 2.0 HAL";
}
HRESULT OpenGLES2Renderer::BeginFrame()
{
m_dirty = true;
glDisable(GL_BLEND);
glEnable(GL_DEPTH_TEST);
glDepthMask(GL_TRUE);
glUseProgram(m_shaderProgram);
SceneLightGLES2 lightData[3];
int lightCount = std::min(static_cast<int>(m_lights.size()), 3);
for (int i = 0; i < lightCount; ++i) {
const auto& src = m_lights[i];
lightData[i].color[0] = src.color.r;
lightData[i].color[1] = src.color.g;
lightData[i].color[2] = src.color.b;
lightData[i].color[3] = src.color.a;
lightData[i].position[0] = src.position.x;
lightData[i].position[1] = src.position.y;
lightData[i].position[2] = src.position.z;
lightData[i].position[3] = src.positional;
lightData[i].direction[0] = src.direction.x;
lightData[i].direction[1] = src.direction.y;
lightData[i].direction[2] = src.direction.z;
lightData[i].direction[3] = src.directional;
}
for (int i = 0; i < lightCount; ++i) {
std::string base = "u_lights[" + std::to_string(i) + "]";
glUniform4fv(glGetUniformLocation(m_shaderProgram, (base + ".color").c_str()), 1, lightData[i].color);
glUniform4fv(glGetUniformLocation(m_shaderProgram, (base + ".position").c_str()), 1, lightData[i].position);
glUniform4fv(glGetUniformLocation(m_shaderProgram, (base + ".direction").c_str()), 1, lightData[i].direction);
}
glUniform1i(glGetUniformLocation(m_shaderProgram, "u_lightCount"), lightCount);
return DD_OK;
}
void OpenGLES2Renderer::EnableTransparency()
{
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glDepthMask(GL_FALSE);
}
void OpenGLES2Renderer::SubmitDraw(
DWORD meshId,
const D3DRMMATRIX4D& modelViewMatrix,
const D3DRMMATRIX4D& worldMatrix,
const D3DRMMATRIX4D& viewMatrix,
const Matrix3x3& normalMatrix,
const Appearance& appearance
)
{
auto& mesh = m_meshs[meshId];
glUniformMatrix4fv(glGetUniformLocation(m_shaderProgram, "u_modelViewMatrix"), 1, GL_FALSE, &modelViewMatrix[0][0]);
glUniformMatrix3fv(glGetUniformLocation(m_shaderProgram, "u_normalMatrix"), 1, GL_FALSE, &normalMatrix[0][0]);
glUniformMatrix4fv(glGetUniformLocation(m_shaderProgram, "u_projectionMatrix"), 1, GL_FALSE, &m_projection[0][0]);
glUniform4f(
glGetUniformLocation(m_shaderProgram, "u_color"),
appearance.color.r / 255.0f,
appearance.color.g / 255.0f,
appearance.color.b / 255.0f,
appearance.color.a / 255.0f
);
glUniform1f(glGetUniformLocation(m_shaderProgram, "u_shininess"), appearance.shininess);
if (appearance.textureId != NO_TEXTURE_ID) {
glUniform1i(glGetUniformLocation(m_shaderProgram, "u_useTexture"), 1);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, m_textures[appearance.textureId].glTextureId);
glUniform1i(glGetUniformLocation(m_shaderProgram, "u_texture"), 0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
}
else {
glUniform1i(glGetUniformLocation(m_shaderProgram, "u_useTexture"), 0);
}
glBindBuffer(GL_ARRAY_BUFFER, mesh.vboPositions);
GLint posLoc = glGetAttribLocation(m_shaderProgram, "a_position");
glEnableVertexAttribArray(posLoc);
glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, nullptr);
glBindBuffer(GL_ARRAY_BUFFER, mesh.vboNormals);
GLint normLoc = glGetAttribLocation(m_shaderProgram, "a_normal");
glEnableVertexAttribArray(normLoc);
glVertexAttribPointer(normLoc, 3, GL_FLOAT, GL_FALSE, 0, nullptr);
GLint texLoc = glGetAttribLocation(m_shaderProgram, "a_texCoord");
if (appearance.textureId != NO_TEXTURE_ID) {
glBindBuffer(GL_ARRAY_BUFFER, mesh.vboTexcoords);
glEnableVertexAttribArray(texLoc);
glVertexAttribPointer(texLoc, 2, GL_FLOAT, GL_FALSE, 0, nullptr);
}
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mesh.ibo);
glDrawElements(GL_TRIANGLES, static_cast<GLsizei>(mesh.indices.size()), GL_UNSIGNED_SHORT, nullptr);
glDisableVertexAttribArray(posLoc);
glDisableVertexAttribArray(normLoc);
glDisableVertexAttribArray(texLoc);
}
HRESULT OpenGLES2Renderer::FinalizeFrame()
{
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
glUseProgram(0);
return DD_OK;
}
void OpenGLES2Renderer::Resize(int width, int height, const ViewportTransform& viewportTransform)
{
m_width = width;
m_height = height;
m_viewportTransform = viewportTransform;
SDL_DestroySurface(m_renderedImage);
m_renderedImage = SDL_CreateSurface(m_width, m_height, SDL_PIXELFORMAT_RGBA32);
glViewport(0, 0, m_width, m_height);
}
void OpenGLES2Renderer::Clear(float r, float g, float b)
{
m_dirty = true;
glEnable(GL_DEPTH_TEST);
glDepthMask(GL_TRUE);
glClearColor(r, g, b, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
}
void OpenGLES2Renderer::Flip()
{
if (m_dirty) {
SDL_GL_SwapWindow(DDWindow);
m_dirty = false;
}
}
void CreateOrthoMatrix(float left, float right, float bottom, float top, D3DRMMATRIX4D& outMatrix)
{
float near = -1.0f;
float far = 1.0f;
float rl = right - left;
float tb = top - bottom;
float fn = far - near;
outMatrix[0][0] = 2.0f / rl;
outMatrix[0][1] = 0.0f;
outMatrix[0][2] = 0.0f;
outMatrix[0][3] = 0.0f;
outMatrix[1][0] = 0.0f;
outMatrix[1][1] = 2.0f / tb;
outMatrix[1][2] = 0.0f;
outMatrix[1][3] = 0.0f;
outMatrix[2][0] = 0.0f;
outMatrix[2][1] = 0.0f;
outMatrix[2][2] = -2.0f / fn;
outMatrix[2][3] = 0.0f;
outMatrix[3][0] = -(right + left) / rl;
outMatrix[3][1] = -(top + bottom) / tb;
outMatrix[3][2] = -(far + near) / fn;
outMatrix[3][3] = 1.0f;
}
void OpenGLES2Renderer::Draw2DImage(Uint32 textureId, const SDL_Rect& srcRect, const SDL_Rect& dstRect)
{
m_dirty = true;
glDisable(GL_DEPTH_TEST);
glDepthMask(GL_FALSE);
glUseProgram(m_shaderProgram);
float color[] = {1.0f, 1.0f, 1.0f, 1.0f};
float blank[] = {0.0f, 0.0f, 0.0f, 0.0f};
glUniform4fv(glGetUniformLocation(m_shaderProgram, "u_lights[0].color"), 1, color);
glUniform4fv(glGetUniformLocation(m_shaderProgram, "u_lights[0].position"), 1, blank);
glUniform4fv(glGetUniformLocation(m_shaderProgram, "u_lights[0].direction"), 1, blank);
glUniform1i(glGetUniformLocation(m_shaderProgram, "u_lightCount"), 1);
glUniform4f(glGetUniformLocation(m_shaderProgram, "u_color"), 1.0f, 1.0f, 1.0f, 1.0f);
glUniform1f(glGetUniformLocation(m_shaderProgram, "u_shininess"), 0.0f);
float left = -m_viewportTransform.offsetX / m_viewportTransform.scale;
float right = (m_width - m_viewportTransform.offsetX) / m_viewportTransform.scale;
float top = -m_viewportTransform.offsetY / m_viewportTransform.scale;
float bottom = (m_height - m_viewportTransform.offsetY) / m_viewportTransform.scale;
D3DRMMATRIX4D projection;
CreateOrthoMatrix(left, right, bottom, top, projection);
D3DRMMATRIX4D identity = {{1.f, 0.f, 0.f, 0.f}, {0.f, 1.f, 0.f, 0.f}, {0.f, 0.f, 1.f, 0.f}, {0.f, 0.f, 0.f, 1.f}};
glUniformMatrix4fv(glGetUniformLocation(m_shaderProgram, "u_modelViewMatrix"), 1, GL_FALSE, &identity[0][0]);
glUniformMatrix3fv(glGetUniformLocation(m_shaderProgram, "u_normalMatrix"), 1, GL_FALSE, &identity[0][0]);
glUniformMatrix4fv(glGetUniformLocation(m_shaderProgram, "u_projectionMatrix"), 1, GL_FALSE, &projection[0][0]);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glActiveTexture(GL_TEXTURE0);
glUniform1i(glGetUniformLocation(m_shaderProgram, "u_useTexture"), 1);
const GLES2TextureCacheEntry& texture = m_textures[textureId];
glBindTexture(GL_TEXTURE_2D, texture.glTextureId);
glUniform1i(glGetUniformLocation(m_shaderProgram, "u_texture"), 0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
float texW = texture.width;
float texH = texture.height;
float u1 = srcRect.x / texW;
float v1 = srcRect.y / texH;
float u2 = (srcRect.x + srcRect.w) / texW;
float v2 = (srcRect.y + srcRect.h) / texH;
float x1 = static_cast<float>(dstRect.x);
float y1 = static_cast<float>(dstRect.y);
float x2 = x1 + dstRect.w;
float y2 = y1 + dstRect.h;
GLfloat vertices[] = {x1, y1, u1, v1, x2, y1, u2, v1, x1, y2, u1, v2, x2, y2, u2, v2};
GLint posLoc = glGetAttribLocation(m_shaderProgram, "a_position");
GLint texLoc = glGetAttribLocation(m_shaderProgram, "a_texCoord");
glEnableVertexAttribArray(posLoc);
glEnableVertexAttribArray(texLoc);
glVertexAttribPointer(posLoc, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(GLfloat), vertices);
glVertexAttribPointer(texLoc, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(GLfloat), vertices + 2);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
glDisableVertexAttribArray(posLoc);
glDisableVertexAttribArray(texLoc);
glBindTexture(GL_TEXTURE_2D, 0);
glUseProgram(0);
}
void OpenGLES2Renderer::Download(SDL_Surface* target)
{
glFinish();
glReadPixels(0, 0, m_width, m_height, GL_RGBA, GL_UNSIGNED_BYTE, m_renderedImage->pixels);
SDL_Rect srcRect = {
static_cast<int>(m_viewportTransform.offsetX),
static_cast<int>(m_viewportTransform.offsetY),
static_cast<int>(target->w * m_viewportTransform.scale),
static_cast<int>(target->h * m_viewportTransform.scale),
};
SDL_Surface* bufferClone = SDL_CreateSurface(target->w, target->h, SDL_PIXELFORMAT_RGBA32);
if (!bufferClone) {
SDL_Log("SDL_CreateSurface: %s", SDL_GetError());
return;
}
SDL_BlitSurfaceScaled(m_renderedImage, &srcRect, bufferClone, nullptr, SDL_SCALEMODE_NEAREST);
// Flip image vertically into target
SDL_Rect rowSrc = {0, 0, bufferClone->w, 1};
SDL_Rect rowDst = {0, 0, bufferClone->w, 1};
for (int y = 0; y < bufferClone->h; ++y) {
rowSrc.y = y;
rowDst.y = bufferClone->h - 1 - y;
SDL_BlitSurface(bufferClone, &rowSrc, target, &rowDst);
}
SDL_DestroySurface(bufferClone);
}