GLESシェーダベースのソリューションです。 Android test
#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
#include <EGL/egl.h>
#include <GLES2/gl2.h>
#define LOGI(...) (printf("(I): " __VA_ARGS__))
#define LOGW(...) (printf("(W): " __VA_ARGS__))
#define LOGE(...) (printf("(E): " __VA_ARGS__))
static GLuint gTextureProgram;
static GLuint gvTexturePositionHandle;
static GLuint gvTextureTexCoordsHandle;
static GLuint gvTextureSamplerHandle;
static const char gSimpleVS[] =
"attribute vec4 position;\n"
"attribute vec2 texCoords;\n"
"varying vec2 outTexCoords;\n"
"\nvoid main(void) {\n"
" outTexCoords = texCoords;\n"
" gl_Position = position;\n"
"}\n\n";
static const char gSimpleFS[] =
"precision mediump float;\n\n"
"varying vec2 outTexCoords;\n"
"uniform sampler2D texture;\n"
"\nvoid main(void) {\n"
" gl_FragColor = texture2D(texture, outTexCoords);\n"
"}\n\n";
static void checkGlError(const char* op) {
GLint error;
for (error = glGetError(); error; error = glGetError()) {
LOGE("after %s() glError (0x%x)\n", op, error);
}
}
static GLuint loadShader(GLenum shaderType, const char* pSource) {
GLuint shader = glCreateShader(shaderType);
if (shader) {
glShaderSource(shader, 1, &pSource, NULL);
glCompileShader(shader);
GLint compiled = 0;
glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
if (!compiled) {
GLint infoLen = 0;
glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &infoLen);
if (infoLen) {
char* buf = (char*) malloc(infoLen);
if (buf) {
glGetShaderInfoLog(shader, infoLen, NULL, buf);
LOGE("Could not compile shader %d:\n%s\n",
shaderType, buf);
free(buf);
}
glDeleteShader(shader);
shader = 0;
}
}
}
return shader;
}
GLuint createProgram(const char* pVertexSource, const char* pFragmentSource) {
GLuint vertexShader = loadShader(GL_VERTEX_SHADER, pVertexSource);
if (!vertexShader) {
return 0;
}
GLuint pixelShader = loadShader(GL_FRAGMENT_SHADER, pFragmentSource);
if (!pixelShader) {
return 0;
}
GLuint program = glCreateProgram();
if (program) {
glAttachShader(program, vertexShader);
checkGlError("glAttachShader");
glAttachShader(program, pixelShader);
checkGlError("glAttachShader");
glLinkProgram(program);
GLint linkStatus = GL_FALSE;
glGetProgramiv(program, GL_LINK_STATUS, &linkStatus);
if (linkStatus != GL_TRUE) {
GLint bufLength = 0;
glGetProgramiv(program, GL_INFO_LOG_LENGTH, &bufLength);
if (bufLength) {
char* buf = (char*) malloc(bufLength);
if (buf) {
glGetProgramInfoLog(program, bufLength, NULL, buf);
LOGE("Could not link program:\n%s\n", buf);
free(buf);
}
}
glDeleteProgram(program);
program = 0;
}
}
return program;
}
bool setupGraphics(void) {
gTextureProgram = createProgram(gSimpleVS, gSimpleFS);
if (!gTextureProgram) {
return false;
}
gvTexturePositionHandle = glGetAttribLocation(gTextureProgram, "position"); checkGlError("glGetAttribLocation");
gvTextureTexCoordsHandle = glGetAttribLocation(gTextureProgram, "texCoords"); checkGlError("glGetAttribLocation");
gvTextureSamplerHandle = glGetUniformLocation(gTextureProgram, "texture"); checkGlError("glGetAttribLocation");
return true;
}
const GLfloat gTriangleVertices[] = { 0.0f, 0.5f, -0.5f, -0.5f,
0.5f, -0.5f };
#define FLOAT_SIZE_BYTES 4;
const GLint TRIANGLE_VERTICES_DATA_STRIDE_BYTES = 5 * FLOAT_SIZE_BYTES;
const GLfloat gTriangleVerticesData[] = {
// X, Y, Z, U, V
-1.0f, -1.0f, 0, 0.f, 0.f,
1.0f, -1.0f, 0, 1.f, 0.f,
-1.0f, 1.0f, 0, 0.f, 1.f,
1.0f, 1.0f, 0, 1.f, 1.f,
};
void glDrawTex(void) {
if (!gTextureProgram) {
if(!setupGraphics()) {
LOGE("Could not set up graphics.\n");
return;
}
}
glUseProgram(gTextureProgram); checkGlError("glUseProgram");
glVertexAttribPointer(gvTexturePositionHandle, 3, GL_FLOAT, GL_FALSE,
TRIANGLE_VERTICES_DATA_STRIDE_BYTES, gTriangleVerticesData);
checkGlError("glVertexAttribPointer");
glVertexAttribPointer(gvTextureTexCoordsHandle, 2, GL_FLOAT, GL_FALSE,
TRIANGLE_VERTICES_DATA_STRIDE_BYTES, &gTriangleVerticesData[3]);
checkGlError("glVertexAttribPointer");
glEnableVertexAttribArray(gvTexturePositionHandle);
glEnableVertexAttribArray(gvTextureTexCoordsHandle);
checkGlError("glEnableVertexAttribArray");
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
checkGlError("glDrawArrays");
glUseProgram(0); checkGlError("glUseProgram");
}
static GLuint gPixelsTexture;
void glDrawPixels(GLsizei width, GLsizei height, GLenum format, GLenum type, const GLvoid * data){
if(!gPixelsTexture) glGenTextures(1, &gPixelsTexture);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, gPixelsTexture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, GL_RGBA, type, data);
glDrawTex();
glBindTexture(GL_TEXTURE_2D, 0);
}