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// Copyright 2017 The Emscripten Authors. All rights reserved.
// Emscripten is available under two separate licenses, the MIT license and the
// University of Illinois/NCSA Open Source License. Both these licenses can be
// found in the LICENSE file.
#define GL_GLEXT_PROTOTYPES
#include <GLES/gl.h>
#include <GLES/glext.h>
#include <GLES2/gl2.h>
#include <stdio.h>
#include <emscripten.h>
#include <emscripten/html5.h>
#include <assert.h>
#include <string.h>
#define GL_CALL( x ) \
{ \
x; \
GLenum error = glGetError(); \
if( error != GL_NO_ERROR ) { \
printf( "GL ERROR: %d, %s\n", (int)error, #x ); \
assert(false); \
} \
} \
int main()
{
emscripten_set_canvas_element_size( "#canvas", 100, 100 );
EmscriptenWebGLContextAttributes attrs;
emscripten_webgl_init_context_attributes(&attrs);
EMSCRIPTEN_WEBGL_CONTEXT_HANDLE context = emscripten_webgl_create_context( "#canvas", &attrs );
if (!context)
{
printf("Skipped: WebGL is not supported.\n");
return 0;
}
emscripten_webgl_make_context_current(context);
GLuint shader;
GL_CALL( shader = glCreateShader(GL_VERTEX_SHADER) );
GLint value = -97631;
GL_CALL( glGetShaderiv(shader, GL_SHADER_SOURCE_LENGTH, &value) );
assert(value == 0);
const GLchar* tempSource = (const GLchar*)"";
GL_CALL( glShaderSource(shader, 1, &tempSource, NULL) );
value = -97631;
GL_CALL( glGetShaderiv(shader, GL_SHADER_SOURCE_LENGTH, &value) );
assert(value == 0);
tempSource = (const GLchar*)"void main() { gl_Position = vec4(0); }";
GL_CALL( glShaderSource(shader, 1, &tempSource, NULL) );
value = -97631;
GL_CALL( glGetShaderiv(shader, GL_SHADER_SOURCE_LENGTH, &value) );
assert(value == strlen(tempSource) + 1);
EMSCRIPTEN_RESULT res = emscripten_webgl_destroy_context(context);
assert(res == EMSCRIPTEN_RESULT_SUCCESS);
return 0;
}
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