blob: f7270020d4ccbc3f32a0392c518d4c4b5e836f34 [file] [log] [blame]
/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "RenderDirectView.h"
#include "VideoTex.h"
#include "glError.h"
#include "shader.h"
#include "shader_simpleTex.h"
#include <log/log.h>
#include <math/mat4.h>
namespace android {
namespace automotive {
namespace evs {
namespace support {
bool RenderDirectView::activate() {
// Ensure GL is ready to go...
if (!prepareGL()) {
ALOGE("Error initializing GL");
return false;
}
// Load our shader program if we don't have it already
if (!mShaderProgram) {
mShaderProgram = buildShaderProgram(vtxShader_simpleTexture,
pixShader_simpleTexture,
"simpleTexture");
if (!mShaderProgram) {
ALOGE("Error building shader program");
return false;
}
}
// Construct our video texture
mTexture.reset(new VideoTex(sDisplay));
if (!mTexture) {
ALOGE("Failed to set up video texture");
// TODO: For production use, we may actually want to fail in this case, but not yet...
// return false;
}
return true;
}
void RenderDirectView::deactivate() {
// Release our video texture
// We can't hold onto it because some other Render object might need the same camera
// TODO: If start/stop costs become a problem, we could share video textures
mTexture = nullptr;
}
bool RenderDirectView::drawFrame(const BufferDesc& tgtBuffer,
const BufferDesc& imageBuffer) {
// Tell GL to render to the given buffer
if (!attachRenderTarget(tgtBuffer)) {
ALOGE("Failed to attached render target");
return false;
}
// Select our screen space simple texture shader
glUseProgram(mShaderProgram);
// Set up the model to clip space transform (identity matrix if we're modeling in screen space)
GLint loc = glGetUniformLocation(mShaderProgram, "cameraMat");
if (loc < 0) {
ALOGE("Couldn't set shader parameter 'cameraMat'");
return false;
} else {
const android::mat4 identityMatrix;
glUniformMatrix4fv(loc, 1, false, identityMatrix.asArray());
}
// Bind the texture and assign it to the shader's sampler
mTexture->refresh(imageBuffer);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, mTexture->glId());
GLint sampler = glGetUniformLocation(mShaderProgram, "tex");
if (sampler < 0) {
ALOGE("Couldn't set shader parameter 'tex'");
return false;
} else {
// Tell the sampler we looked up from the shader to use texture slot 0 as its source
glUniform1i(sampler, 0);
}
// We want our image to show up opaque regardless of alpha values
glDisable(GL_BLEND);
// Draw a rectangle on the screen
GLfloat vertsCarPos[] = { -1.0, 1.0, 0.0f, // left top in window space
1.0, 1.0, 0.0f, // right top
-1.0, -1.0, 0.0f, // left bottom
1.0, -1.0, 0.0f // right bottom
};
// TODO: We're flipping horizontally here, but should do it only for specified cameras!
GLfloat vertsCarTex[] = { 1.0f, 1.0f, // left top
0.0f, 1.0f, // right top
1.0f, 0.0f, // left bottom
0.0f, 0.0f // right bottom
};
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, vertsCarPos);
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, vertsCarTex);
glEnableVertexAttribArray(0);
glEnableVertexAttribArray(1);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
glDisableVertexAttribArray(0);
glDisableVertexAttribArray(1);
// Now that everything is submitted, release our hold on the texture resource
detachRenderTarget();
// Wait for the rendering to finish
glFinish();
detachRenderTarget();
return true;
}
} // namespace support
} // namespace evs
} // namespace automotive
} // namespace android